33,180 research outputs found

    Physiological responses of women to simulated weightlessness: A review of the first female bed-rest study

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    Subjects were exposed to centrifugation, to lower body negative pressure (LBNP), and to exericse stress both before and after bed rest. Areas studied were centrifugation tolerance, fluid electrolyte changes and hematology, tolerance to LBNP, physical working capacity, biochemistries, blood fibrinolytic activity, female metabolic and hormonal responses, circadian alterations, and gynecology. Results were compared with the responses observed in similarly bed-rested male subjects. The bed-rested females showed deconditioning responses similar to those of the males, although with some differences. Results indicate that women are capable of coping with exposure to weightlessness and, moreover, that they may be more sensitive subjects for evaluating countermeasures to weightlessness and developing criteria for assessing applicants for shuttle voyages

    The Impact of Foreclosures on Neighboring Housing Sales

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    Housing foreclosures likely have little neighborhood impacts if there are few foreclosures in a neighborhood and the foreclosed housing can resell quickly. However, when there are both many foreclosures and a sluggish housing market, foreclosures can lead to neighborhood destabilization, which should cause house prices to further fall. This paper measures the impact of foreclosures on housing sales using a unique dataset from St. Louis County, Missouri. Results show an expected decline the sales price of neighboring sales but the marginal impact of foreclosures seems to decline with an increase in the number of foreclosures. These results are robust to a variety of neighborhood control variables and spatial econometric techniques.

    Population Aging, Savings Behavior and Capital Markets

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    Population aging is just beginning to hit the industrialized countries in full force, and it will have a tremendous impact on capital markets. In this paper, we argue that the capital market effects of population aging are particularly strong in continental European economies such as Germany, France, and Italy, with their large and ailing pay-as-you-go public pension systems, relatively thin capital markets, and poor capital performance. The younger generations in these countries are quite aware of the need to provide for more retirement income through own private saving, and these effects will be accentuated by fundamental pension reforms that aim at more pre-funding. Population aging changes households' savings behavior and portfolio composition, and much more assets will be invested on the stock market. Capital markets will grow in size, and active institutional investors such as pension funds will become more important in continental European countries. These changes are likely to have beneficial side effects in terms of improved capital efficiency, total factor productivity, and growth. Looking at the effects of population aging on savings behavior and capital markets therefore adds a new dimension to the continuing debate about advantages and disadvantages of pay-as-you-go and fully funded pension systems.

    Single particle spectra of charge transfer insulators by cluster perturbation theory - the correlated band structure of NiO

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    We propose a many-body method for band-structure calculations in strongly correlated electron systems and apply it to NiO. The method may be viewed as a translationally invariant version of the cluster method of Fujimori and Minami. Thereby the Coulomb interaction within the d-shells is treated by exact diagonalization and the d-shells then are coupled to a solid by an extension of the cluster perturbation theory due to Senechal et al. The method is computationally no more demanding than a conventional band structure calculation and for NiO we find good agreement between the calculated single particle spectral function and the experimentally measured band structure.Comment: Revtex-file, 15 pages with 12 eps figure

    ADN: An Information-Centric Networking Architecture for the Internet of Things

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    Forwarding data by name has been assumed to be a necessary aspect of an information-centric redesign of the current Internet architecture that makes content access, dissemination, and storage more efficient. The Named Data Networking (NDN) and Content-Centric Networking (CCNx) architectures are the leading examples of such an approach. However, forwarding data by name incurs storage and communication complexities that are orders of magnitude larger than solutions based on forwarding data using addresses. Furthermore, the specific algorithms used in NDN and CCNx have been shown to have a number of limitations. The Addressable Data Networking (ADN) architecture is introduced as an alternative to NDN and CCNx. ADN is particularly attractive for large-scale deployments of the Internet of Things (IoT), because it requires far less storage and processing in relaying nodes than NDN. ADN allows things and data to be denoted by names, just like NDN and CCNx do. However, instead of replacing the waist of the Internet with named-data forwarding, ADN uses an address-based forwarding plane and introduces an information plane that seamlessly maps names to addresses without the involvement of end-user applications. Simulation results illustrate the order of magnitude savings in complexity that can be attained with ADN compared to NDN.Comment: 10 page

    On the communication cost of entanglement transformations

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    We study the amount of communication needed for two parties to transform some given joint pure state into another one, either exactly or with some fidelity. Specifically, we present a method to lower bound this communication cost even when the amount of entanglement does not increase. Moreover, the bound applies even if the initial state is supplemented with unlimited entanglement in the form of EPR pairs, and the communication is allowed to be quantum mechanical. We then apply the method to the determination of the communication cost of asymptotic entanglement concentration and dilution. While concentration is known to require no communication whatsoever, the best known protocol for dilution, discovered by Lo and Popescu [Phys. Rev. Lett. 83(7):1459--1462, 1999], requires a number of bits to be exchanged which is of the order of the square root of the number of EPR pairs. Here we prove a matching lower bound of the same asymptotic order, demonstrating the optimality of the Lo-Popescu protocol up to a constant factor and establishing the existence of a fundamental asymmetry between the concentration and dilution tasks. We also discuss states for which the minimal communication cost is proportional to their entanglement, such as the states recently introduced in the context of ``embezzling entanglement'' [W. van Dam and P. Hayden, quant-ph/0201041].Comment: 9 pages, 1 figure. Added a reference and some further explanations. In v3 some arguments are given in more detai

    Preliminary assessment of cognitive impairments in canine idiopathic epilepsy

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    In humans, epilepsy can induce or accelerate cognitive impairment (CI). There is emerging evidence of CI in dogs with idiopathic epilepsy (IE) from recent epidemiological studies. The aim of our study was to assess CI in dogs with IE using two tests of cognitive dysfunction designed for use in a clinical setting. Dogs with IE (n=17) were compared against controls (n=18) in their performance in two tasks; a spatial working memory task and a problem-solving task. In addition, owners completed the Canine Cognitive Dysfunction Rating (CCDR) scale for their dog. The groups did not differ statistically with respect to age and breed. Dogs with IE performed significantly worse than controls on the spatial working memory task (P=0.016), but not on the problem solving task (P=0.683). CCDR scores were significantly higher in the IE group (P=0.016); however, no dogs reach the recommended threshold score for CCD diagnosis. Our preliminary data suggest that dogs with IE exhibit impairments in a spatial working memory task. Further research is required to explore the effect of IE on other cognitive abilities in dogs with a larger sample, characterising the age of onset, nature and progression of any impairments and the impact of anti-epileptic drugs
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